This project includes a protocol to collect human blood samples to be used for research studies and to validate research assays used in evaluation of clinical trials immunogencity results. The VRC is using the samples to study specific immune responses to HIV infection in order to characterize protective responses that can prevent new infection in uninfected individuals, as well as define those responses that lead to successful control of viral replication in persons already infected with HIV. Because of the lack of an adequate animal model it is necessary to utilize human peripheral blood cells. We wish to define the specific human immune responses to HIV infection using human peripheral blood mononuclear cells as a model. These sample collection protocols also support VRC research on other pathogens and vaccines.